Stamped laminated stacks for parking pawl, parking gear and parking anchor

Abstract

A parking brake ( 10 ) for a transmission ( 12 ) of a motorized vehicle ( 14 ). An anchor ( 24 ) is located to support an actuator ( 26 ) interposed between the anchor ( 24 ) and a parking pawl ( 22 ) when the parking pawl ( 22 ) is in the engaged position with a toothed parking gear ( 20 ). The anchor ( 24 ) is defined by a plurality of stacked laminas ( 30 ). Each of the plurality of stacked laminas ( 30 ) is rigid and has at least one peripherally extending surface ( 32 ), wherein the at least one peripherally extending surface ( 32 ) of at least two of the plurality of stacked laminas cooperate to define at least one load-bearing surface ( 34 ), and wherein the plurality of stacked laminas ( 30 ) are secured together to prevent relative movement of any one of the plurality of stacked laminas ( 30 ) with respect to another of the plurality of stacked laminas ( 30 ) when a load is transmitted through the parking pawl ( 22 ) from the at least one load-bearing surface ( 34 ).

What is claimed is: 
     
       1. In a parking brake ( 10 ) for a transmission ( 12 ) of a motorized vehicle ( 14 ) for transporting at least one of passenger and cargo, where the transmission ( 12 ) receives rotary input torque from a power source ( 16 ) and transmits the rotary input torque to an output load ( 18 ) to propel the vehicle ( 14 ), and the parking brake ( 10 ) stops rotation of the output load ( 18 ) and prevents movement of the vehicle ( 14 ), the improvement comprising:
 an actuator ( 26 ) movable between a first position and a second position; 
 a toothed parking gear ( 20 ) connected to the output load ( 18 ) and having an axis of rotation; 
 a pivotable parking pawl ( 22 ) engageable with the toothed parking gear ( 20 ) for stopping rotational motion of the output load ( 18 ) in an engaged position even if the vehicle is unattended, the pivotable parking pawl ( 22 ) rotatable with respect to a pivot axis in response to movement of the actuator ( 26 ) between the first position and the second position, the parking pawl ( 22 ) pivotable between a disengaged position spaced from the toothed parking gear ( 20 ) and the engaged position contacting the toothed parking gear ( 20 ); and 
 a stationary anchor ( 24 ) separate from the actuator and spaced from the actuator ( 26 ) when in the second position, while being located to support the actuator ( 26 ) interposed between the anchor ( 24 ) and the parking pawl ( 22 ) when the actuator ( 26 ) is in the first position driving the parking pawl ( 22 ) into the engaged position with the toothed parking gear ( 20 ), the anchor ( 24 ) defined by a plurality of stacked laminas ( 30 ), each of the plurality of stacked laminas ( 30 ) being rigid and having at least one peripherally extending surface ( 32 ), wherein the at least one peripherally extending surface ( 32 ) of at least two of the plurality of stacked laminas ( 30 ) cooperate to define at least one load-bearing surface ( 34 ) engaging the actuator ( 26 ) when in the first position, and wherein the plurality of stacked laminas ( 30 ) are secured together to prevent relative movement of any one of the plurality of stacked laminas ( 30 ) with respect to another of the plurality of stacked laminas ( 30 ) when a load is transmitted through the anchor ( 24 ) from the at least one load-bearing surface ( 34 ). 
 
     
     
       2. The improvement of  claim 1  further comprising:
 at least one of the plurality of stacked laminas ( 30 ) having a different peripheral contour ( 36 ) defining at least one chamfered load-bearing surface ( 38 ) on the anchor ( 24 ). 
 
     
     
       3. The improvement of  claim 2  further comprising:
 the at least one chamfered load-bearing surface ( 38 ) on the anchor ( 24 ) facing the actuator ( 26 ) for engagement with the actuator ( 26 ) during movement between the first position and the second position. 
 
     
     
       4. The improvement of  claim 1  further comprising:
 the parking pawl ( 22 ) defined by a plurality of stacked laminas ( 40 ), each of the plurality of stacked laminas ( 40 ) being rigid and having at least one peripherally extending surface ( 42 ), where the at least one peripherally extending surface ( 42 ) of at least two of the plurality of stacked laminas ( 40 ) cooperate to define at least one load-bearing surface ( 44 ), where the plurality of stacked laminas ( 40 ) are secured together to prevent relative movement of any one of the plurality of stacked laminas ( 40 ) with respect to another of the plurality of stacked laminas ( 40 ) when a load is transmitted through the parking pawl ( 22 ) from the at least one load bearing surface ( 44 ). 
 
     
     
       5. The improvement of  claim 4  further comprising:
 at least one of the plurality of stacked laminas ( 40 ) having a different peripheral contour ( 46 ) defining at least one chamfered load-bearing surface ( 48 ) on the parking pawl ( 22 ). 
 
     
     
       6. The improvement of  claim 5  further comprising:
 the at least one chamfered load-bearing surface ( 48 ) on the parking pawl ( 22 ) facing the actuator ( 26 ) for engagement with the actuator ( 26 ) during movement between the first position and the second position. 
 
     
     
       7. The improvement of  claim 1  further comprising:
 the pivot axis of the parking pawl ( 22 ) being parallel to and offset from the axis of rotation of the toothed parking gear ( 20 ). 
 
     
     
       8. The improvement of  claim 1  further comprising:
 a spring ( 28 ) biasing the pivotable parking pawl ( 22 ) normally toward the disengaged position. 
 
     
     
       9. The improvement of  claim 1  further comprising:
 the toothed parking gear ( 20 ) defined by a plurality of stacked laminas ( 50 ), each of the plurality of stacked laminas ( 50 ) being rigid and having at least one peripherally extending surface ( 52 ), where the at least one peripherally extending surface ( 52 ) of at least two of the plurality of stacked laminas ( 50 ) cooperate to define a load-bearing surface ( 54 ), and where the plurality of stacked laminas ( 50 ) are secured together to prevent relative movement of any one of the plurality of stacked laminas ( 50 ) with respect to another of the plurality of stacked laminas ( 50 ) when a load is transmitted through the toothed parking gear ( 20 ) from the load-bearing surface ( 54 ). 
 
     
     
       10. In a parking brake ( 10 ) for a transmission ( 12 ) of a motorized vehicle ( 14 ) for transporting at least one of passenger and cargo, where the transmission ( 12 ) receives rotary input torque from a power source ( 16 ) and transmits the rotary input torque to an output load ( 18 ) to propel the vehicle ( 14 ), and the parking brake ( 10 ) stops rotation of the output load ( 18 ) and prevents movement of the vehicle ( 14 ), the improvement comprising:
 an actuator ( 26 ) movable between a first position and a second position; 
 a toothed parking gear ( 20 ) connected to the output load ( 18 ) and having an axis of rotation, the toothed parking gear ( 20 ) defined by a plurality of stacked laminas ( 50 ), each of the plurality of stacked laminas ( 50 ) being rigid and having at least one peripherally extending surface ( 52 ), where the at least one peripherally extending surface ( 52 ) of at least two of the plurality of stacked laminas ( 50 ) cooperate to define at least one load-bearing surface ( 54 ), and where the plurality of stacked laminas ( 50 ) are secured together to prevent relative movement of any one of the plurality of stacked laminas ( 50 ) with respect to another of the plurality of stacked laminas ( 50 ) when a load is transmitted through the toothed parking gear ( 20 ) from the at least one load-bearing surface ( 54 ); and 
 a pivotable parking pawl ( 22 ) engageable with the toothed parking gear ( 20 ) for stopping rotational motion of the output load ( 18 ) in an engaged position even if the vehicle ( 14 ) is unattended, the pivotable parking pawl ( 22 ) rotatable with respect to a pivot axis in response to movement of the actuator ( 26 ) between the first position and the second position, the pivot axis of the parking pawl ( 22 ) being parallel to and offset from the axis of rotation of the toothed parking gear ( 20 ), the parking pawl ( 22 ) pivotable between a disengaged position spaced from the toothed parking gear ( 20 ) and an engaged position contacting the toothed parking gear ( 20 ), the parking pawl ( 22 ) defined by a plurality of stacked laminas ( 40 ), each of the plurality of stacked laminas ( 40 ) being rigid and having at least one peripherally extending surface ( 42 ), where the at least one peripherally extending surface ( 42 ) of at least two of the plurality of stacked laminas ( 40 ) cooperate to define at least one load-bearing surface ( 44 ) engaging the at least one load bearing surface ( 54 ) of the toothed parking gear ( 20 ), where the plurality of stacked laminas ( 40 ) are secured together to prevent relative movement of any one of the plurality of stacked laminas ( 40 ) with respect to another of the plurality of stacked laminas ( 40 ) when a load is transmitted through the parking pawl ( 22 ) from the at least one load-bearing surface ( 44 ), at least one of the plurality of stacked laminas ( 40 ) having a different peripheral contour ( 46 ) defining at least one chamfered load-bearing surface ( 48 ) on the stacked laminas ( 40 ) of the parking pawl ( 22 ), the at least one chamfered load-bearing surface ( 48 ) on the parking pawl ( 22 ) facing the actuator ( 26 ) for engagement with the actuator ( 26 ) during movement between the first position and the second position; and 
 an anchor ( 24 ) located to support the actuator ( 26 ) interposed between the anchor ( 24 ) and the parking pawl ( 22 ) when the parking pawl ( 22 ) is in the engaged position with the toothed parking gear ( 20 ), the anchor ( 24 ) defined by a plurality of stacked laminas ( 30 ), each of the plurality of stacked laminas ( 30 ) being rigid and having at least one peripherally extending surface ( 32 ), wherein the at least one peripherally extending surface ( 32 ) of at least two of the plurality of stacked laminas ( 30 ) cooperate to define at least one load-bearing surface ( 34 ) engaging the actuator ( 26 ), and wherein the plurality of stacked laminas ( 30 ) are secured together to prevent relative movement of any one of the plurality of stacked laminas ( 30 ) with respect to another of the plurality of stacked laminas ( 30 ) when a load is transmitted through the parking pawl ( 22 ) from the at least one load-bearing surface ( 34 ). 
 
     
     
       11. The improvement of  claim 10  further comprising:
 at least one of the plurality of stacked laminas ( 30 ) having a different peripheral contour ( 36 ) defining at least one chamfered load-bearing surface ( 38 ) on the anchor ( 24 ). 
 
     
     
       12. The improvement of  claim 11  further comprising:
 the at least one chamfered load-bearing surface ( 38 ) on the anchor ( 24 ) facing the actuator ( 26 ) for engagement with the actuator ( 26 ) during movement between the first position and the second position. 
 
     
     
       13. The improvement of  claim 12  further comprising:
 a spring ( 28 ) biasing the pivotable parking pawl ( 22 ) normally toward the disengaged position.